While implantable electronic systems continue to show tremendous promise, major deficiencies remain in the area of packaging and interconnection. Foster-Miller, in this proposed effort, will develop and demonstrate a new, low-cost, highly reliable, hermetic packaging technology for implantable electronics. This new packaging platform is based on remarkable new class of materials known as thermoplastic Liquid Crystal Polymers (LCPs). Foster-Miller has been developing an electronic packaging technology based on these innovative LCPs for a host of electronic and optoelectronic applications. More recently, Foster-Miller has been applying their LCP film technology to the biomedical world, in particular in the area of neural prostheses. Foster-Miller is currently funded by NINDS to develop LCPbased microribbon cables as a direct replacement for existing silicon and polyimide cables. This work has shown great early promise with the LCP materials proving both extremely insulative (electrically) and biologically inert. This proposed effort builds on this early promise to expand the technology to address the packaging of implanted electronics. In addition to their excellent electrical properties, LCPs have barrier properties comparable to glass, several orders of magnitude greater than most other polymers, thus offering the potential of a plastic hermetic packaging technology, a hitherto unimaginable concept.